As described by Matz, Snack Food Technology, conventional corn chip processes begin with a corn meal or corn masa. Both white and yellow corn of the dent type are added to a vat containing heated water and a proportionate amount of lime. The mixture is heated to the boiling point, the heat is cut off, and the contents of the vat are permitted to stand undisturbed for 10 to 20 hours. During this time, the corn hulls are hydrated and partially hydrolyzed. The hulls are softened to a jelly-like consistency and are easily removed later in the process. The starch is also gelatinzed. By the end of the steeping period, the corn kernels have absorbed approximately 50% by weight water. The hulls are removed in a washer by jets of water which also remove any remaining lime. The washed kernels are then transferred to a stone mill where they are ground into a dough or masa. The masa is formed (usually by hand) into large cylindrical loaves and fed into hydraulically powered extrusion presses. The cylindrical chamber of the press contains a closely fitting piston which forces the dough through a die plate having a series of slot-like ports. A cutting device severs the extruded strands into pieces. Alternatively, the dough can be rolled out into a thin sheet from which shapes can be cut. Dough pieces fall directly into heated cooking oil. After the moisture content of the cut dough has been reduced to about a few percent, the resulting cooked corn product is salted, cooled, and packaged.
Such conventional processes of producing corn chips suffer from various disadvantages including the fact that the chips are gritty and subject to toothpacking.
One method of addressing such disadvantages is described in commonly-assigned U.S. Pat. No. 4,645,679 which describes a method for the production of corn chips which involves comminuting a hydrated starch material such as potato starch with hydrated corn.